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-rw-r--r--kernel/padata.c71
1 files changed, 68 insertions, 3 deletions
diff --git a/kernel/padata.c b/kernel/padata.c
index 868f947166d7..f262c9a4e70a 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -131,6 +131,7 @@ int padata_do_parallel(struct padata_instance *pinst,
padata->cb_cpu = cb_cpu;
target_cpu = padata_cpu_hash(pd);
+ padata->cpu = target_cpu;
queue = per_cpu_ptr(pd->pqueue, target_cpu);
spin_lock(&queue->parallel.lock);
@@ -275,11 +276,51 @@ static void padata_reorder(struct parallel_data *pd)
return;
}
+static void invoke_padata_reorder(struct work_struct *work)
+{
+ struct padata_parallel_queue *pqueue;
+ struct parallel_data *pd;
+
+ local_bh_disable();
+ pqueue = container_of(work, struct padata_parallel_queue, reorder_work);
+ pd = pqueue->pd;
+ padata_reorder(pd);
+ local_bh_enable();
+}
+
static void padata_reorder_timer(unsigned long arg)
{
struct parallel_data *pd = (struct parallel_data *)arg;
+ unsigned int weight;
+ int target_cpu, cpu;
- padata_reorder(pd);
+ cpu = get_cpu();
+
+ /* We don't lock pd here to not interfere with parallel processing
+ * padata_reorder() calls on other CPUs. We just need any CPU out of
+ * the cpumask.pcpu set. It would be nice if it's the right one but
+ * it doesn't matter if we're off to the next one by using an outdated
+ * pd->processed value.
+ */
+ weight = cpumask_weight(pd->cpumask.pcpu);
+ target_cpu = padata_index_to_cpu(pd, pd->processed % weight);
+
+ /* ensure to call the reorder callback on the correct CPU */
+ if (cpu != target_cpu) {
+ struct padata_parallel_queue *pqueue;
+ struct padata_instance *pinst;
+
+ /* The timer function is serialized wrt itself -- no locking
+ * needed.
+ */
+ pinst = pd->pinst;
+ pqueue = per_cpu_ptr(pd->pqueue, target_cpu);
+ queue_work_on(target_cpu, pinst->wq, &pqueue->reorder_work);
+ } else {
+ padata_reorder(pd);
+ }
+
+ put_cpu();
}
static void padata_serial_worker(struct work_struct *serial_work)
@@ -323,10 +364,21 @@ void padata_do_serial(struct padata_priv *padata)
int cpu;
struct padata_parallel_queue *pqueue;
struct parallel_data *pd;
+ int reorder_via_wq = 0;
pd = padata->pd;
cpu = get_cpu();
+
+ /* We need to run on the same CPU padata_do_parallel(.., padata, ..)
+ * was called on -- or, at least, enqueue the padata object into the
+ * correct per-cpu queue.
+ */
+ if (cpu != padata->cpu) {
+ reorder_via_wq = 1;
+ cpu = padata->cpu;
+ }
+
pqueue = per_cpu_ptr(pd->pqueue, cpu);
spin_lock(&pqueue->reorder.lock);
@@ -336,7 +388,13 @@ void padata_do_serial(struct padata_priv *padata)
put_cpu();
- padata_reorder(pd);
+ /* If we're running on the wrong CPU, call padata_reorder() via a
+ * kernel worker.
+ */
+ if (reorder_via_wq)
+ queue_work_on(cpu, pd->pinst->wq, &pqueue->reorder_work);
+ else
+ padata_reorder(pd);
}
EXPORT_SYMBOL(padata_do_serial);
@@ -384,8 +442,14 @@ static void padata_init_pqueues(struct parallel_data *pd)
struct padata_parallel_queue *pqueue;
cpu_index = 0;
- for_each_cpu(cpu, pd->cpumask.pcpu) {
+ for_each_possible_cpu(cpu) {
pqueue = per_cpu_ptr(pd->pqueue, cpu);
+
+ if (!cpumask_test_cpu(cpu, pd->cpumask.pcpu)) {
+ pqueue->cpu_index = -1;
+ continue;
+ }
+
pqueue->pd = pd;
pqueue->cpu_index = cpu_index;
cpu_index++;
@@ -393,6 +457,7 @@ static void padata_init_pqueues(struct parallel_data *pd)
__padata_list_init(&pqueue->reorder);
__padata_list_init(&pqueue->parallel);
INIT_WORK(&pqueue->work, padata_parallel_worker);
+ INIT_WORK(&pqueue->reorder_work, invoke_padata_reorder);
atomic_set(&pqueue->num_obj, 0);
}
}